Try ringing a local framer...
I had some certificates (5m swimming and 'employee of the day' - it's easy when you're the boss...) to frame and thought there's no way it would be cheaper in a real store.
It was cheaper in a real store.
I literally died of shock*.

We charge around £40 to frame a map. Depends on the frame obviously.
Can't stick down the custom printed ones(the ones with your house right in the middle,for example) so they never really get totally flat.
Older ones can be dry mounted so the folds etc mostly disappear.